diff --git a/extern/glew-es/SConscript b/extern/glew-es/SConscript
index b7c713c08c4..7552ce84067 100644
--- a/extern/glew-es/SConscript
+++ b/extern/glew-es/SConscript
@@ -6,7 +6,9 @@ Import('env')
 
 sources = ['src/glew.c']
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
+
 if env['WITH_BF_GLEW_MX']:
     defs += ['GLEW_MX']
 incs = ['include']
diff --git a/extern/glew/SConscript b/extern/glew/SConscript
index d825968806e..a9687383a0c 100644
--- a/extern/glew/SConscript
+++ b/extern/glew/SConscript
@@ -6,7 +6,9 @@ Import('env')
 
 sources = ['src/glew.c']
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
+
 if env['WITH_BF_GLEW_MX']:
     defs += ['GLEW_MX']
 
diff --git a/intern/ghost/SConscript b/intern/ghost/SConscript
index 025559e11a4..78566210047 100644
--- a/intern/ghost/SConscript
+++ b/intern/ghost/SConscript
@@ -48,7 +48,8 @@ sources.remove('intern' + os.sep + 'GHOST_ContextWGL.cpp')
 
 pf = ['GHOST_DisplayManager', 'GHOST_System', 'GHOST_SystemPaths', 'GHOST_Window', 'GHOST_DropTarget', 'GHOST_NDOFManager', 'GHOST_Context']
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_GL_EGL']:
     defs.append('WITH_EGL')
diff --git a/intern/glew-mx/SConscript b/intern/glew-mx/SConscript
index 5c70958816c..546470d020c 100644
--- a/intern/glew-mx/SConscript
+++ b/intern/glew-mx/SConscript
@@ -5,9 +5,8 @@ import os
 Import('env')
 
 sources = ['intern/glew-mx.c']
-
-defs = env['BF_GL_DEFINITIONS']
-
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 incs = [
     '.',
     env['BF_GLEW_INC'],
diff --git a/intern/opencolorio/SConscript b/intern/opencolorio/SConscript
index c2fb95a4d95..6be6a5ed90c 100644
--- a/intern/opencolorio/SConscript
+++ b/intern/opencolorio/SConscript
@@ -30,7 +30,9 @@ Import('env')
 sources = env.Glob('*.cc')
 
 incs = '. ../guardedalloc ../../source/blender/blenlib'
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_OCIO']:
     defs.append('WITH_OCIO')
diff --git a/source/blender/blenfont/SConscript b/source/blender/blenfont/SConscript
index 61d2ca9b12d..fdb5f669597 100644
--- a/source/blender/blenfont/SConscript
+++ b/source/blender/blenfont/SConscript
@@ -48,7 +48,8 @@ incs = [
 
 incs.extend(Split(env['BF_FREETYPE_INC']))
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if sys.platform == 'win32' or env['OURPLATFORM'] == 'linuxcross':
     defs.append('_WIN32')
diff --git a/source/blender/blenkernel/SConscript b/source/blender/blenkernel/SConscript
index 20ac329f2cf..853e2b05433 100644
--- a/source/blender/blenkernel/SConscript
+++ b/source/blender/blenkernel/SConscript
@@ -72,7 +72,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_SMOKE']:
     defs.append('WITH_SMOKE')
diff --git a/source/blender/editors/animation/SConscript b/source/blender/editors/animation/SConscript
index ed4b794cbce..11eea4dc4f2 100644
--- a/source/blender/editors/animation/SConscript
+++ b/source/blender/editors/animation/SConscript
@@ -43,7 +43,8 @@ incs = [
     '../../windowmanager',
     ]
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_INTERNATIONAL']:
     defs.append('WITH_INTERNATIONAL')
diff --git a/source/blender/editors/armature/SConscript b/source/blender/editors/armature/SConscript
index 97bc1a138b3..8249dc00c17 100644
--- a/source/blender/editors/armature/SConscript
+++ b/source/blender/editors/armature/SConscript
@@ -45,7 +45,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['OURPLATFORM'] in ('win32-vc', 'win32-mingw', 'linuxcross', 'win64-vc', 'win64-mingw'):
     incs += ' ' + env['BF_PTHREADS_INC']
diff --git a/source/blender/editors/gpencil/SConscript b/source/blender/editors/gpencil/SConscript
index ab42bad52dc..8e2ac5dc61e 100644
--- a/source/blender/editors/gpencil/SConscript
+++ b/source/blender/editors/gpencil/SConscript
@@ -47,7 +47,8 @@ incs = [
     '../../windowmanager',
     ]
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_INTERNATIONAL']:
     defs.append('WITH_INTERNATIONAL')
diff --git a/source/blender/editors/interface/SConscript b/source/blender/editors/interface/SConscript
index 5af8bba5a9f..7584fd8ad46 100644
--- a/source/blender/editors/interface/SConscript
+++ b/source/blender/editors/interface/SConscript
@@ -46,7 +46,8 @@ incs = [
     '../../windowmanager',
     ]
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['OURPLATFORM'] in ('win32-vc', 'win32-mingw', 'win64-vc', 'win64-mingw'):
     if env['WITH_BF_IME']:
diff --git a/source/blender/editors/mask/SConscript b/source/blender/editors/mask/SConscript
index bcbaaa34960..c4e6daaf5df 100644
--- a/source/blender/editors/mask/SConscript
+++ b/source/blender/editors/mask/SConscript
@@ -29,7 +29,8 @@ Import ('env')
 
 sources = env.Glob('*.c')
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 incs = [
     '#/intern/guardedalloc',
diff --git a/source/blender/editors/mesh/SConscript b/source/blender/editors/mesh/SConscript
index 122a7501e58..8b41241cea1 100644
--- a/source/blender/editors/mesh/SConscript
+++ b/source/blender/editors/mesh/SConscript
@@ -29,7 +29,8 @@ Import ('env')
 
 sources = env.Glob('*.c')
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 incs = [
     '#/intern/guardedalloc',
diff --git a/source/blender/editors/physics/SConscript b/source/blender/editors/physics/SConscript
index 983d1c4b4ba..98d6be6d0bc 100644
--- a/source/blender/editors/physics/SConscript
+++ b/source/blender/editors/physics/SConscript
@@ -46,7 +46,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['OURPLATFORM'] in ('win32-vc', 'win32-mingw', 'linuxcross', 'win64-vc', 'win64-mingw'):
     incs += ' ' + env['BF_PTHREADS_INC']
diff --git a/source/blender/editors/render/SConscript b/source/blender/editors/render/SConscript
index cbb7988695b..ada0c6cf251 100644
--- a/source/blender/editors/render/SConscript
+++ b/source/blender/editors/render/SConscript
@@ -49,7 +49,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['OURPLATFORM'] in ('win32-vc', 'win32-mingw', 'linuxcross', 'win64-vc', 'win64-mingw'):
     incs += ' ' + env['BF_PTHREADS_INC']
diff --git a/source/blender/editors/screen/SConscript b/source/blender/editors/screen/SConscript
index f5442c7ea63..355e3065312 100644
--- a/source/blender/editors/screen/SConscript
+++ b/source/blender/editors/screen/SConscript
@@ -46,7 +46,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['OURPLATFORM'] in ('win32-vc', 'win32-mingw', 'linuxcross', 'win64-vc', 'win64-mingw'):
     incs += ' ' + env['BF_PTHREADS_INC']
diff --git a/source/blender/editors/sculpt_paint/SConscript b/source/blender/editors/sculpt_paint/SConscript
index 233f562fcc7..ba20337548a 100644
--- a/source/blender/editors/sculpt_paint/SConscript
+++ b/source/blender/editors/sculpt_paint/SConscript
@@ -29,7 +29,8 @@ Import ('env')
 
 sources = env.Glob('*.c')
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 incs = [
     '#/intern/guardedalloc',
diff --git a/source/blender/editors/space_action/SConscript b/source/blender/editors/space_action/SConscript
index 20f31dd6399..28572f64fb8 100644
--- a/source/blender/editors/space_action/SConscript
+++ b/source/blender/editors/space_action/SConscript
@@ -29,7 +29,8 @@ Import ('env')
 
 sources = env.Glob('*.c')
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 incs = [
     '#/intern/guardedalloc',
diff --git a/source/blender/editors/space_buttons/SConscript b/source/blender/editors/space_buttons/SConscript
index 07fe17e302b..b9cba3139c2 100644
--- a/source/blender/editors/space_buttons/SConscript
+++ b/source/blender/editors/space_buttons/SConscript
@@ -47,7 +47,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_INTERNATIONAL']:
     defs.append('WITH_INTERNATIONAL')
diff --git a/source/blender/editors/space_clip/SConscript b/source/blender/editors/space_clip/SConscript
index 8fec4ebf0fa..46ad04a1478 100644
--- a/source/blender/editors/space_clip/SConscript
+++ b/source/blender/editors/space_clip/SConscript
@@ -29,7 +29,8 @@ Import ('env')
 
 sources = env.Glob('*.c')
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 incs = [
     '#/intern/guardedalloc',
diff --git a/source/blender/editors/space_console/SConscript b/source/blender/editors/space_console/SConscript
index 87d12fe34bd..f189cd3920a 100644
--- a/source/blender/editors/space_console/SConscript
+++ b/source/blender/editors/space_console/SConscript
@@ -29,7 +29,8 @@ Import ('env')
 
 sources = env.Glob('*.c')
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 incs = [
     '../include',
diff --git a/source/blender/editors/space_file/SConscript b/source/blender/editors/space_file/SConscript
index 85c3e073922..b37cba15281 100644
--- a/source/blender/editors/space_file/SConscript
+++ b/source/blender/editors/space_file/SConscript
@@ -46,7 +46,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_OPENJPEG']:
     defs.append('WITH_OPENJPEG')
diff --git a/source/blender/editors/space_graph/SConscript b/source/blender/editors/space_graph/SConscript
index ac23e8ee4e7..216ce2de334 100644
--- a/source/blender/editors/space_graph/SConscript
+++ b/source/blender/editors/space_graph/SConscript
@@ -44,7 +44,8 @@ incs = [
     '../../windowmanager',
     ]
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_AUDASPACE']:
     defs += env['BF_AUDASPACE_DEF']
diff --git a/source/blender/editors/space_image/SConscript b/source/blender/editors/space_image/SConscript
index e983db431b4..43181b437f5 100644
--- a/source/blender/editors/space_image/SConscript
+++ b/source/blender/editors/space_image/SConscript
@@ -48,7 +48,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_INTERNATIONAL']:
     defs.append('WITH_INTERNATIONAL')
diff --git a/source/blender/editors/space_info/SConscript b/source/blender/editors/space_info/SConscript
index 378940805da..c64e263179b 100644
--- a/source/blender/editors/space_info/SConscript
+++ b/source/blender/editors/space_info/SConscript
@@ -47,7 +47,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_INTERNATIONAL']:
     defs.append('WITH_INTERNATIONAL')
diff --git a/source/blender/editors/space_logic/SConscript b/source/blender/editors/space_logic/SConscript
index 067073fab22..f22a716e502 100644
--- a/source/blender/editors/space_logic/SConscript
+++ b/source/blender/editors/space_logic/SConscript
@@ -46,7 +46,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_GAMEENGINE']:
     defs.append('WITH_GAMEENGINE')
diff --git a/source/blender/editors/space_nla/SConscript b/source/blender/editors/space_nla/SConscript
index 9e743d918b9..d37bb201b81 100644
--- a/source/blender/editors/space_nla/SConscript
+++ b/source/blender/editors/space_nla/SConscript
@@ -44,7 +44,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_INTERNATIONAL']:
     defs.append('WITH_INTERNATIONAL')
diff --git a/source/blender/editors/space_node/SConscript b/source/blender/editors/space_node/SConscript
index 435a78f1b7e..a79fc8c18bd 100644
--- a/source/blender/editors/space_node/SConscript
+++ b/source/blender/editors/space_node/SConscript
@@ -1,3 +1,4 @@
+
 #!/usr/bin/env python
 #
 # ***** BEGIN GPL LICENSE BLOCK *****
@@ -48,7 +49,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 cf = []
 if env['OURPLATFORM'] in ('win32-vc', 'win64-vc'):
diff --git a/source/blender/editors/space_outliner/SConscript b/source/blender/editors/space_outliner/SConscript
index cc02c9555a9..ae3e960124f 100644
--- a/source/blender/editors/space_outliner/SConscript
+++ b/source/blender/editors/space_outliner/SConscript
@@ -29,7 +29,8 @@ Import ('env')
 
 sources = env.Glob('*.c')
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs == env['BF_GL_DEFINITIONS']
 
 incs = [
     '#/intern/guardedalloc',
diff --git a/source/blender/editors/space_script/SConscript b/source/blender/editors/space_script/SConscript
index e749780a4aa..c03a61ec197 100644
--- a/source/blender/editors/space_script/SConscript
+++ b/source/blender/editors/space_script/SConscript
@@ -44,7 +44,8 @@ incs = [
     '../../windowmanager',
     ]
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_PYTHON']:
     defs.append('WITH_PYTHON')
diff --git a/source/blender/editors/space_sequencer/SConscript b/source/blender/editors/space_sequencer/SConscript
index 8ec1cddce10..32a79feac76 100644
--- a/source/blender/editors/space_sequencer/SConscript
+++ b/source/blender/editors/space_sequencer/SConscript
@@ -44,7 +44,8 @@ incs = [
     '../../windowmanager',
     ]
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_AUDASPACE']:
     defs += env['BF_AUDASPACE_DEF']
diff --git a/source/blender/editors/space_text/SConscript b/source/blender/editors/space_text/SConscript
index 8ee9bd745dd..c3518f857b6 100644
--- a/source/blender/editors/space_text/SConscript
+++ b/source/blender/editors/space_text/SConscript
@@ -29,7 +29,8 @@ Import ('env')
 
 sources = env.Glob('*.c')
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 incs = [
     '#/intern/guardedalloc',
diff --git a/source/blender/editors/space_time/SConscript b/source/blender/editors/space_time/SConscript
index 5a9e9a4cb42..86437b9c258 100644
--- a/source/blender/editors/space_time/SConscript
+++ b/source/blender/editors/space_time/SConscript
@@ -42,6 +42,7 @@ incs = [
     '../../windowmanager',
     ]
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 env.BlenderLib('bf_editors_space_time', sources, incs, defs, libtype=['core'], priority=[65])
diff --git a/source/blender/editors/space_view3d/SConscript b/source/blender/editors/space_view3d/SConscript
index 78f24948070..2ec9aa7e4af 100644
--- a/source/blender/editors/space_view3d/SConscript
+++ b/source/blender/editors/space_view3d/SConscript
@@ -29,7 +29,8 @@ Import ('env')
 
 sources = env.Glob('*.c')
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 incs = [
     '#/intern/guardedalloc',
diff --git a/source/blender/editors/transform/SConscript b/source/blender/editors/transform/SConscript
index 1a2e9ab074a..823e94bd0ae 100644
--- a/source/blender/editors/transform/SConscript
+++ b/source/blender/editors/transform/SConscript
@@ -45,7 +45,8 @@ incs = [
     '../../windowmanager',
     ]
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_INTERNATIONAL']:
     defs.append('WITH_INTERNATIONAL')
diff --git a/source/blender/editors/util/SConscript b/source/blender/editors/util/SConscript
index d695a848f4e..8162f955464 100644
--- a/source/blender/editors/util/SConscript
+++ b/source/blender/editors/util/SConscript
@@ -29,7 +29,8 @@ Import ('env')
 
 sources = env.Glob('*.c')
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 incs = [
     '#/intern/guardedalloc',
diff --git a/source/blender/editors/uvedit/SConscript b/source/blender/editors/uvedit/SConscript
index 7153d25188b..501240ca4de 100644
--- a/source/blender/editors/uvedit/SConscript
+++ b/source/blender/editors/uvedit/SConscript
@@ -27,7 +27,8 @@
 
 Import ('env')
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 sources = env.Glob('*.c')
 
diff --git a/source/blender/gpu/SConscript b/source/blender/gpu/SConscript
index 880a6d14e26..d27d5b09b56 100644
--- a/source/blender/gpu/SConscript
+++ b/source/blender/gpu/SConscript
@@ -30,7 +30,8 @@ Import ('env')
 sources = env.Glob('intern/*.c')
 sources += env.Glob('shaders/*.c')
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 incs = [
     '.',
diff --git a/source/blender/makesrna/SConscript b/source/blender/makesrna/SConscript
index 089fbe11307..e9f937cb939 100644
--- a/source/blender/makesrna/SConscript
+++ b/source/blender/makesrna/SConscript
@@ -59,7 +59,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_SMOKE']:
     defs.append('WITH_SMOKE')
diff --git a/source/blender/makesrna/intern/SConscript b/source/blender/makesrna/intern/SConscript
index 0a9f9eec08c..4cb2a584240 100644
--- a/source/blender/makesrna/intern/SConscript
+++ b/source/blender/makesrna/intern/SConscript
@@ -53,7 +53,8 @@ makesrna_tool = env.Clone()
 rna = env.Clone()
 makesrna_tool.Append(CCFLAGS = '-DBASE_HEADER="\\"source/blender/makesrna/\\"" ')
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 incs = [
     '#/intern/guardedalloc',
diff --git a/source/blender/nodes/SConscript b/source/blender/nodes/SConscript
index 9c2cc825f14..c41e399ec29 100644
--- a/source/blender/nodes/SConscript
+++ b/source/blender/nodes/SConscript
@@ -53,7 +53,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_PYTHON']:
     incs += ' ' + env['BF_PYTHON_INC']
diff --git a/source/blender/python/SConscript b/source/blender/python/SConscript
index 7c5156605fc..eeca09e02e5 100644
--- a/source/blender/python/SConscript
+++ b/source/blender/python/SConscript
@@ -62,7 +62,8 @@ sources = env.Glob('bmesh/*.c')
 env.BlenderLib( libname = 'bf_python_bmesh', sources = Split(sources), includes = Split(incs), defines = defs, libtype = ['core','player'], priority = [362,165])
 
 # generic
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if is_debug:
     defs.append('_DEBUG')
@@ -79,7 +80,8 @@ env.BlenderLib( libname = 'bf_python_mathutils', sources = Split(sources), inclu
 
 
 # bpy
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if is_debug:
     defs.append('_DEBUG')
diff --git a/source/blender/windowmanager/SConscript b/source/blender/windowmanager/SConscript
index e05bc130c20..4f2e295e872 100644
--- a/source/blender/windowmanager/SConscript
+++ b/source/blender/windowmanager/SConscript
@@ -55,7 +55,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_PYTHON']:
     defs.append('WITH_PYTHON')
diff --git a/source/gameengine/BlenderRoutines/SConscript b/source/gameengine/BlenderRoutines/SConscript
index 9bce7b78bf4..ea14092943a 100644
--- a/source/gameengine/BlenderRoutines/SConscript
+++ b/source/gameengine/BlenderRoutines/SConscript
@@ -29,7 +29,8 @@ Import ('env')
 
 sources = env.Glob('*.cpp')
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 incs = [
     '.',
diff --git a/source/gameengine/GamePlayer/common/SConscript b/source/gameengine/GamePlayer/common/SConscript
index b8fb9cbd2e2..dc105491c98 100644
--- a/source/gameengine/GamePlayer/common/SConscript
+++ b/source/gameengine/GamePlayer/common/SConscript
@@ -68,7 +68,8 @@ incs = [
     '#/intern/glew-mx',
     ]
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_PYTHON']:
     incs.extend(Split(env['BF_PYTHON_INC']))
diff --git a/source/gameengine/GamePlayer/ghost/SConscript b/source/gameengine/GamePlayer/ghost/SConscript
index c31bd0c2f08..ac756281b15 100644
--- a/source/gameengine/GamePlayer/ghost/SConscript
+++ b/source/gameengine/GamePlayer/ghost/SConscript
@@ -74,7 +74,8 @@ incs = [
 incs.append(env['BF_PTHREADS_INC'])
 incs.append(env['BF_BOOST_INC'])
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_PYTHON']:
     incs += Split(env['BF_PYTHON_INC'])
diff --git a/source/gameengine/Ketsji/SConscript b/source/gameengine/Ketsji/SConscript
index 5b2807d8172..d8dfd3d9bca 100644
--- a/source/gameengine/Ketsji/SConscript
+++ b/source/gameengine/Ketsji/SConscript
@@ -30,7 +30,8 @@ import sys
 Import ('env')
 
 sources = env.Glob('*.cpp')
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 incs = [
     '.',
diff --git a/source/gameengine/Physics/Bullet/SConscript b/source/gameengine/Physics/Bullet/SConscript
index 30287553a10..5c5b1fe6ea6 100644
--- a/source/gameengine/Physics/Bullet/SConscript
+++ b/source/gameengine/Physics/Bullet/SConscript
@@ -52,7 +52,8 @@ incs = ' '.join(incs)
 
 incs += ' ' + env['BF_BULLET_INC']
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_PYTHON']:
     incs += ' ' + env['BF_PYTHON_INC']
diff --git a/source/gameengine/Rasterizer/RAS_OpenGLRasterizer/SConscript b/source/gameengine/Rasterizer/RAS_OpenGLRasterizer/SConscript
index 93905f733dc..ce520df2a21 100644
--- a/source/gameengine/Rasterizer/RAS_OpenGLRasterizer/SConscript
+++ b/source/gameengine/Rasterizer/RAS_OpenGLRasterizer/SConscript
@@ -3,7 +3,8 @@ Import ('env')
 
 sources = env.Glob('*.cpp')
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 incs = [
     '.',
diff --git a/source/gameengine/Rasterizer/SConscript b/source/gameengine/Rasterizer/SConscript
index c0d725ad957..a643f46e39a 100644
--- a/source/gameengine/Rasterizer/SConscript
+++ b/source/gameengine/Rasterizer/SConscript
@@ -46,7 +46,8 @@ incs = [
     '#source/blender/makesdna',
     ]
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['WITH_BF_PYTHON']:
     incs.extend(Split(env['BF_PYTHON_INC']))
diff --git a/source/gameengine/VideoTexture/SConscript b/source/gameengine/VideoTexture/SConscript
index b1b02db3ebc..dc708904309 100644
--- a/source/gameengine/VideoTexture/SConscript
+++ b/source/gameengine/VideoTexture/SConscript
@@ -58,7 +58,8 @@ incs = [
     ]
 incs = ' '.join(incs)
 
-defs = env['BF_GL_DEFINITIONS']
+defs = []
+defs += env['BF_GL_DEFINITIONS']
 
 if env['OURPLATFORM'] in ('win32-vc', 'win64-vc','win32-mingw', 'win64-mingw'):
     if env['BF_DEBUG']: